Adjusting-screw for revolving chairs.



PATBNTED JAN. 2, 1906.

H. G. HUNN. ADJUSTING SURE-W FOR REVOLVING CHAIRS.

PPL n1 FILED APR UNITED STATES PATENT OFFICE.

ADJUSTING-SCREW FOR REVOLVING CHAIRS.

Specification of Letters Patent.

Patented Jan. 2, 19C6.

Application filed April 4:, 1905. $erial N0. 253,811.

T0 at whmn it TIMI/y concern:

Be it known that I, HowARD G. HUNN, a citizen of the United States, residing at New York city, in the county of New York and State of New York, have invented a new and useful Adjusting-Screw for Revolving Chairs, of which the following is a specification.

This invention relates generally to adjusting screws for revolving chairs, and more particularly to that class in which the turning of the chair has no efiect whateverin causing it to be moved from its adjusted plane.

The object of the invention is to simplify the construction and render more efficient the operation of a device of this character by providing a more extended bearing for the seat-supporting spindle and to cause the connection between the raising and lowering mechanism and the leg-supporting head to be more stable in character, thereby to prevent any tilting or rocking movement of the chair relatively to the head.

With the above and other objects in view, as will appear as the nature of the invention is better understood, the same consists in the novel construction and combination of parts of an adjusting-screw for a revolving chair, as will be hereinafter fully described and claimed.

In the accompanying drawings, forming a part of this specification, and in which like characters of reference indicate corresponding parts, Figure l is a view in elevation exhibiting the improvements of the present invention. Fig. 2 is a view in vertical transverse section through the attachment.

Referring to the drawings, 1 designates the leg-supporting head, which, as usual, is made of cast iron and is provided with suitable sockets to receive the legs L. The head maybe made in various ways to suit the different requirements that may arise, and as its exact construction is immaterial to the present invention further description is deemed unnecessary. The head is provided with a longitudinal smooth bore 2, in which is disposed a sleeve 3, provided at its upper end with a laterally-extendin arm 4, preferably integral therewith, the sleeve and arm being by preference made of cast-iron, although the article may be made of any other metal adapted for the purpose. The sleeve is provided with a longitudinal orifice 4, in which fits a seatsupporting spindle 5 ,that is freely rotatable therein, the upper end of the spindle having secured to it in any preferred manner a seat-bracket 6, as usual, which is rigid with the spindle, the lower end or hub 7 of the bracket being adapted to bear upon the upper side of the spindle, and thus permit easy rotation of the supporting-spindle relatively to the sleeve. If desired, antifriction-bearings may be dis posed between the opposed faces of the heads and the sleeves, and as this is a common and well-known expedient for reducing friction in devices of this character illustration thereof is deemed unnecessary.

The arm 4 constitutes a bearing for one end of the adjusting-screw 8, the latter having a threaded engagement with an offset or extension 9, formed on or carried by the leghead, as clearly shown in Fig. 2. The upper terminal 10 of the screw is devoid of threads and works in a vertical orifice formed in the bearing or arm 4,with which it is held operatively combined by a nut 11, secured on its upper end and secured against accidental separation therefrom by a pin or locking-screw 12. The screw carries a hand-wheel 13, either i ntegral therewith or secured thereto, and which is disposed between the bearing 4 and the upper face of the leg-head, the periphery of the wheel being roughened or knurled, as usual, to assist in its turning.

When the chair-seat (not shown) is to be raised or lowered, the hand-wheel 13 is turned in the appropriate direction, thereby raising or lowering the sleeve and with it the seatsupporting spindle, and when the desired adjustment has been secured it will be maintained therein irrespective of any vmovements that may be imparted to the spindle in the use of the chair.

The improvements herein, while simple in character, will be found thoroughly effective for the purpose designed and may be readily adapted to ordinary makes of revolving chairs without requiring any change in their structural arrangement.

Having thus described the invention, what is claimed is An article of the class described comprising a leg-supporting head provided with a longitudinal smooth bore and a threaded offset, an internally and externally smooth sleeve engaging the orifice and having an arm constitutlng a bearing, an adjusting-screw in engagement with the threaded offset and having one end mounted for rotation in the my own I have hereto affixed my signature in arm, a stop secured to the upper end of the the presence of two witnesses. adjusting-screw and bearing upon the arm to hold the screw against disconnection there- 5 from, and an externally-smo0th seat-sup Witnesses:

porting spindle mounted Within the sleeve. GEORGE C. DYER,

In testimony that I claim the foregoing as ARTHUR B. HUNN.

HOWARD G. HUNN. 

